Method for cleaning fabrics



' Patented Sept. 1, 1936 STATES r QOFVFICE METHOD FOR CLEANING memos NoDrawing. Application April 22, 1932, Serial No. 607,005

' 3 Claims;

This invention relates to a soap adapted to be used in conjunctionwithdry cleaning operations, that is in connection with the cleaning ofgarments and similar fabrics with light petroleum solvents such as thosecommonly designated by the terms cleaning solvent and cleaners naphtha,or carbon tetrachloride or other chlorinated solvents or mixtures of anyof these.

The object of the invention is to provide an oil-soluble soap which maybe used with such solvents and which will be miscible in all proportionswith the solvent for dry cleaning purposes and which will also bereadily emulsifiable in water so that it may be removed by laundering.Further objects of the invention are to provide a soap adapted for useby the housewife for home cleaning purposes, to aid and improve thesolvent properties of the cleaning solvent, to provide an agent whichmay be used for removing practically all stains including most of thecommon food stains and other stains such as those from asphalt, roadoil, crank case oil, and the like, spots of which are frequently foundupon clothing and similar fabrics. It is a further object that such acleaning soap shall not weaken or damage fabrics. Nor shall this soap beresponsible for leaving'a disagreeable odor in the fabrics aftercleaning such as is caused by residual free oleic or other unsaturatedfatty acids contained in corresponding soaps commonly used by drycleaners.

I have discovered that the above objects may be accomplished bycombining an ethanolamine soap of a higher saturated fatty acid (or anequivalent soap) with a hydroxylated solvent in the class of the liquidhigher alcohols and alcohol-ethers, such as propyl alcohol, butylcellosolve (butyl ether of ethylene glycol), cyclohexanol, and the like.

The prepared soap may be in the form of a true 40' liquid solution or apaste or an emulsion, and

may or may not contain water, and may or may not contain quantities of alight petroleum sol- Vent of the type mentioned. Preferably however thesoap mixture will contain both water and such as'cleaning solvent.

The ethanolamine soaps of the higher saturated fatty acids are preferredboth because they are oil-soluble; i. e. soluble in light petroleumsolvents and the like, and because they leave no objectionable odors.The hydroxylated solvents mentioned are selected because of their highsolvent properties for the specified soaps and for most food stains, fatstains and oil stains. These solvents also act as blending agents andpromote compatibility. When water is included, it is provided for thepurpose of attacking and softening those spots and stains which havebeen deposited from water solutions or similar liquids. Hereinafterthese spots and stains will be referred to as Water-soluble" although infact they are not neces- 5 sarily strictly soluble in water. Where thepetroleum light solvent is added it acts both to attack and dissolveoils and the like, and possibly more important, to reduce the activityof the water and the alcohols upon delicate fabrics, weak dyes, andsizing or other finishing materials in the fabrics. Thus, said lightsolvent serves to prevent watermarking by water eitherseparately-applied to the spot or contained in the soap composition.

Preferably triethanolamine stearate is employed as the soap because itmeets all of the above requirements in a most satisfactory degree, andbutyl cellosolve is employed as the hydroxylated solvent because itpossesses a high degree of solvent capacity for the stearate and forvarious kinds of stains including most of the food, fat and oil stains.

In the simplest form the'prepared soap will contain merely theethanolamine soap and butyl cellosolve, this alcoholic solvent beingused either in an amount sufiicient only to make a paste or in an amountsuincient to liquefy the soap. However in order' to adapt the preparedsoap for attacking water-soluble stains, water will be added in variousproportions. Where the cleaning soap is otherwise a liquid, the watermay be added either in a quantity small enough to maintain a true liquidor solution form or it maybe added in quantity great enough to form anemulsion, the soap being readily emulsifiable. However, unless modifiedin some manner, the activity of both the water and the alcoholic solventupon some weak dyes is too pronounced and the effect of the alcohol uponsome delicate fabrics is undesirable. The light petroleum solventsmentioned will act as such modifiers both for water and the alcohols.Therefore the prepared soap preferably is diluted with a quantity ofsuch a petroleum solvent in proportions which may vary anywhere betweenabout one to three parts of the solvent to one part of the alcoholicsoap. Here also the water may be in small amount (for example about 10%)to maintain a liquid or solution form, or in greater amount (for exampleto form an emulsion. 50 It is to be noted that the liquid or solutionforms are readily miscible in all proportions with the 7 light petroleumsolvent as well as readily emulsifiable with water.

Any of these soaps may be used for removing spots from fabrics by theapplication of small quantities to the spots. In general there are twoprocedures, one to be employed for the removal of oil stains and thelike, and the other to be employed for the removal of spots laid downfrom water solutions and the like, i. e. the watersoluble spots andstains above mentioned which classification includes many food spots andstains. In the first instance, soap in non-emulsion form is applied tothe spots and worked into the fabric. In this case the soap should be aform containing light petroleum solution in order that this solvent mayserve to dissolve the oily materials and to some extent to loosen grittysubstances and the like and disintegrate the spot sufficiently that thealcoholic solvent may attack and dissolve the stains and the soap mayhave ready access to the fabric in order to exercise its detergentfunction. After the soap composition has been sufficiently worked intothe spots, the fabric may be subsequently washed. Washing may be carriedout with a petroleum light solvent or the like, or the fabric may belaundered with water. In either case the soap on the spot is completelyremoved during the washing operation. Laundering with water completelyremoves the soap because the latter is readily emulsifiable with thewater, and the petroleum solvent likewise readily removes the soapbecause of its free solubility therein. When spots laid down from watersolutions are to be treated, a small amount of water may first beapplied to dampen the spots for the purpose of softening and looseningthe materials in the spots. The soap composition is then applied andworked into the fabric to form an emulsion in situ with the appliedwater. Or a previously prepared emulsion of the soap may be applieddirectly to the spots. In either case the resultant emulsion is wellworked into the fabric until adequate disintegration and solution of thespots and their stains is accomplished.

No further soap treatment is required if the fabric concentrated soapmust be applied to the emulsion on the spots to reduce the-water contentof the emulsion to such a point as to render the resultant soap mixturecompatible with thepetroleum solvent so that all of the soap togetherwith the spot and stains may be removed thereby. By compatible I meanemulsifiable or soluble in the solvent. This operation is necessarybecause the form of emulsion required to remove water-soluble spotscontains so much water as not to be compatible with such light petroleumsolvents, and therefore will not be removed from the fabric when washedtherein. The measure of the amount of concentrated soap required to beadded for the purpose of adequately reducing the emulsion may bedetermined by reason of the fact'that the opacity of the emulsiondisappears when the water content has been sufficiently reduced byadditional concentrated soap. Having obtained this condition the fabricmay be washed in the usual. way with petroleum solvent and the soap willbe completely removed along with the spots and theirstainS.

The invention therefore may be stated as comprising a soap compositionadapted for use in cleaning fabrics either by laundering with water orby washing with petroleum light solvents, wherein the compositioncomprises an ethanolamine soap of the higher saturated fatty acids (suchas triethanolamine stearate) or other suitable oil-soluble soap freefrom the characteristic of leaving residual odors in the fabrics,combined with a liquid higher alcohol or alcohol-ether such as propylalcohol or butyl cellosolve (butyl ether of ethylene glycol), thealcohol or alcohol-ether having a high solvent capacity for the soap andfor most of the stains to which fabrics are commonly subjected. .Thissoap may be in either liquid or paste form. The invention also includessuch a soap combined with a quantity of water either small enough tomaintain a liquid form or sufficient to produce an emulsion. Similarlythe emulsion may be put in either paste or liquid form by variation inthe quantity of water added. -The invention further includes such a soapin liquid or emulsion form combined with two or three times its ownweight of petroleumlight solvent or the like in which the soap isreadily miscible and whereby the activity of contained water andalcoholic solvent is reduced to a degree sufficiently low to avoidinjury to weak dyes and delicate fabrics. The invention resides furtherin the methods of cleaning fabrics or in water according to usuallaundering procedures.

Considering the soap hereof in detail, a desirable form is a liquidcontaining both water and petroleum cleaning solvent. One method ofpreparation of this liquid soap is as follows: A suitable kettle orother receptacle is charged with about 250 pounds of stearic acid andheated to approximately 165 F. until the stearic acid is melted,whereupon the heat is removed. Approximately 2100 pounds (or about 315gallons) of cleaning solvent in the form of the usual light petroleumfraction is then added with constant agitation, and thereafter there areadded about 300 pounds of butyl cellosolve" (butylether of ethyleneglycol) and about 125 pounds of triethanolamine (i. e. insuitable-combining proportions) following which about 225 pounds ofwater (27 gallons) is slowly introduced. Agitation is continued until aclear solution is obtained which requires about 15 minutes. The productis then ready for packaging. In the above example the proportions areapproximately as follows:

' Per cent by weight Pounds Triethanolamine stearate"..- 12 375 Butylcellosolve (CH2OH.CH2OC4H9) 10 300 Water -5. 7 225 Petroleum cleaningsolvent--- 70 2100 For purposes of a satisfactory solution theseproportions may be modifled to a very considerable extent except thatthe water percentage should not be greatly increased if it is desired tomaintain liquidity. Nor is there any necessity for increasing theproportion of butyl cellosolve with respect to the stearate above thatindicated in the example, it being desired merely to insure solubilityof the stearate which function is in part performed by the lightpetroleum solvent. However the proportions of the stearate and butylcellosolve with respect to cleaning solvent may be considerablyincreased, as by doubling. One very satisfactory liquid soap mixturecontains only water.

about 45% of cleaning solvent and is approximately as follows:

. Percent by weight Triethanolamine stearate 25 Butyl cellosolve 20Water.. 10 Cleaning solvent 45 Either of the above cleaning compositionsmay be used for the removal of all of the common food stains, fats andfat stains and stains from asphalt, crank case oil, road oils and thelike such as nowadays frequently are found to have soiled the clothing.The soap is used ordinarily by first applying a small quantity of it tospots to be removed. Normally the water content as given is sufficientto remove "water-soluble stains, i. e. those put down from watersolutions and the like. The other stains are removed principally by thestearate and the butyl cellosolve, although the cleaning solvent itselfperforms a portion of the solvent function, in addition to reducing theactivity of the water and the alcohol upon weak dyes and delicatefabrics. Under these circumstances, after the spot has been well rubbed,the entire garment or other fabric may be immersed and agitated incleaners solvent or other light petroleum solvent, or carbontetrachloride or mixtures of these, whereby the entire garment iscleaned and the soap is removed. 0r after treating the spots with theliquid soap, the garment may be laundered with water in theusual'manner, the soap being completely removedin the laundering. Wherethe spot is largely "water-soluble such as is the case with many foodstains. it is preferable to apply a small amount of water to the stainsuflicient' only to dampen it, and then to apply a small quantity of theliquid soap and work the same into an emulsion with the applied Thegarment may be then laundered, but if it is desired to clean it withpetroleum solvent the emulsion formed on the spot must be somewhatreduced as to water content so that the cleaning solvent will take it upas above developed. 'I'his reduction as accomplished by applying anadditional quantity of 'the liquid soap;

Thereupon the garment may be successfully cleansed by immersion andagitation in the light solvent.

With some fabrics, and especially with certain dyes, the application ofwater to a spot before soap application frequently results inwater-marking the fabrics, this apparently being due to the activity ofthe water before an emulsion is formed. In order to avoid thisdisadvantage, a soap emulsion having an appreciable quantity of water'isprepared from either of the liquid soaps given above, the water contentof the emulsion being such that the water-soluble stains may besatisfactorily treated;'here the cleaning solvent serves to protect thedye and the size or other finish in the fabric against the activity ofthe water. For these purposes about two parts of the liquid soapexamplecontaining 12 /2% of the triethanolamine stearate will becombined with one part of water, and in the example containing 25% oftriethanolamine stearate one part of the liquid soap will be Whenneither the action of the water nor of the alcoholic solvent (butylcellosolve) is a detriment, the petroleum light solvent may be omittedfrom theliquid soap. For example a liquid cleaner which may be readilyused with strong dyes and ordinary fabrics would contain Per centTrlethanolamine. stearate--. .25 "Butyl cellosolve (butyl ether ofethylene glycol) 67% Water 7 Most dyes are not affected by either thebutyl cellosolve or the water, although some red dyes and many greendyes may show some effect and watermarking in these instances is quiteapt to occur. Substantially the only fabric that can be affected is thatcommonly known as celanese, which is an artificial product fromcellulose acetate. For all other purposes this liquid soap is verysatisfactory, since it has marked solvent effects upon all spots andstains. For the purpose sufficiently large proportion of the stearatewith the butyl cellosolve that a paste rather than a liquid is formed;this paste is applicable to nonwater-soluble stains, or to water-solublestains which have first been dampened with water. In

some instances it would be permissible to omit the alcohols as well asthe water, the soap then being worked up with petroleum light solventalone. soaps the fabrics may then be laundered with water or cleanedwith light petroleum solvents or the like as above described inconnection with the other examples, which includes suitable reduction ofany emulsion with a portion of concentrated soap composition where thespotting operations are to be followed by cleansing in light solvent.

In all these cases it is to be understood, as previously pointed out,that the term water-soluble is used to apply to spots and stains whichhave been laid down from water solutions although not all the substancesin the spots may be in themselves strictly soluble in water.

Various equivalents may be employed for the triethanolamine stearate andfor the butyl cellosolve (butyl ether of ethylene glycol) above given.Thus any ethanolamine. soap may be prepared from any of the highersaturated fatty acids. This includes the range from palmitic acid tobehenic acid, the object being to avoid un- After spot-ting fabrics withany of these Again, where water is not required stitute. for the butylcellosolve", other high solvent agents having similar high solventcharacteristics for both the soap and the various stains mentioned maybe employed, these being the liquid higher alcohols or alcohol-ethersbeginning with propyl alcohol and including the cyclohexanol and butylcellosolve mentioned and other alcohol-ethers or cellosolves such as themethyl and ethyl ethers of ethylene glycol and the methyl, ethyl andbutyl ethers of diethylene glycol. These solvents are valuable by reasonof their cyclic or ether characteristics.

Practically all stains can be removed with these cleaners in one way oranother. However, in the case of stains from ink, mercurochrome, iodineand the like, complete removal cannot be effected although the intensityof these stains is greatly reduced. Again substantially all colors andall fabrics may be treated. The only exceptions which have been foundare that sometimes red silks are slightly affected and green silks aresometimes inclined to be water-marked where water is used to dampen thespots prior to soap treatment.

In general there are two methods for the use of the cleaner inconnection with all fabrics and all colors. In conjunction with mostfood stains the best results are obtained by first dampening the spotwith water, applying a small quantity of a non-emulsified form of thecleaning soap hereof and rubbing the soap into the spot until it isthoroughly emulsified with the water which. has been applied, or byapplying a previously prepared emulsion. Where the stains are notattacked by water, as in the case of asphalt stains, petroleum oilstains and various fat stains, the concentrated or non-emulsified soapisrubbed directly on the dry spots. Thereafter the fabric may be launderedwith water or cleaned in any ordinary cleaning solvent as abovedescribed.

- For these reasons the dry cleaning soap here It is to be understoodthat the above disclosures are to be taken as illustrative of theinvention, not

as limiting since obviously many variations may be devised by theskilled operator.

I claim:

1. A method for cleaning fabrics having spots at least partiallywater-soluble, comprising working into the spots a water emulsion of asoap composition containing an oil-soluble ethanolamine soap of a highersaturated fatty acid free from the characteristic of leaving residualodors and a liquid higher alcoholic solvent for the soap, and for manystains, applying to the emulsion a quantity of said soap composition innon-emulsified form for the purpose of reducing the water content of theemulsion on the spots, and subsequently removing the resultant soapmixture from the fabric by washing in a light petroleum cleaningsolvent.

2. A method for removing spots from fabrics comprising working into thespots a water emulsion of a soap composition containing an oil-solubleethanolamine soap of a higher saturated fatty acid, an ether of ethyleneglycol, and a quantity of light petroleum solvent capable of dissolvingthe soap and reducing the activity of the water and the glycol ether,applying to the emulsion a quantity of such soap composition innon-emulsifled form for the purpose of reducing the water content of theemulsion to such a degree that it is compatible with light petroleumsolvents and the like, and subsequently washing the soap mixture fromthe fabric with such a light solvent.

3. A method for removing from fabric spots capable of being softenedwith water, comprising dampening the spots with a small amount of water,working into the dampened spots a quantity of soap composition andforming an emulsion therewith, said composition containing an oilsoluble ethanolamine stearate and an ether of ethylene glycol, applyingto the emulsion a quantity of the soap composition in non-emulsifiedDAVID R. MERRILL.

